AVP is a hormone known for its antidiuretic effect and its effect in regulating arterial pressure. It stimulates several types of receptors: V1 (V1a, V1b) or V2. These receptors are located in particular in the liver, vessels (coronary, renal, cerebral), platelets, kidney, uterus, adrenal glands, pancreas, central nervous system or pituitary gland. AVP thus exerts cardiovascular, hepatic, pancreatic, antidiuretic and platelet-aggregating effects and effects on the central and peripheral nervous system and on the uterine sphere.
The localization of the various receptors is described in: S. Jard et al., Vasopressin and oxytocin receptors: an overview, in Progress in Endocrinology, H. Imura and K. Shizurne ed., Experta Medica, Amsterdam, 1988, 1183-1188, and in the following articles: J. Lab. Clin. Med., 1989, 114 (6), 617-632 and Pharmacol. Rev., 1991, 43 (1), 73-108.
More particularly, AVP V1a receptors are located in numerous peripheral organs and in the brain. They have been cloned in the rat and man and they regulate the majority of known effects of AVP: platelet aggregation; uterine contractions; vessel contraction; contraction of renal mesangial cells; the secretion of aldosterone, of cortisol, of CRF (corticotropin-releasing factor) and of adrenocorticotrophic hormone (ACTH); hepatic glycogenolysis, cell proliferation and the main central effects of AVP (hypothermia, memory, anxiety, affiliation, and the like).
The adrenal cortex is also rich in V1a receptors involved in the production of gluco- and mineralocorticoids (aldosterone and cortisol). Via these receptors, AVP (circulating or synthesized locally) can bring about production of aldosterone with an effectiveness comparable to that of angiotensin II (G. Guillon et al., Endocrinology, 1995, 136 (3), 1285-1295). Cortisol is a powerful regulator of the production of ACTH, the stress hormone.
Recent studies have also shown that the adrenal glands are capable of directly releasing CRF and/or ACTH via the activation of the V1a and/or V1b receptors carried by the cells of the medulla (G. Mazzocchi et al., Peptides, 1997, 18 (2), 191-195; E. Grazzini et al., J. Clin. Endocrinol. Metab., 1999, 84 (6), 2195-2203).
The V1a receptors are also a more specific label for small cell lung cancers (SCLC) (P. J. Woll et al., Biochem. Biophys. Res. Commun., 1989, 164 (1), 66-73). Thus, the compounds according to the present invention are obvious diagnostic tools and offer a novel therapeutic approach for controlling the proliferation of these tumours and their detection, at an early stage too (radiolabelling; SPECT (Single Photon Emission Computed Tomography); PET scan (Positron Emission Tomography Scan)).
The V1b receptors were initially identified in the adenohypophysis of various animal species (rat, pig, cow, sheep, and the like), including in man (S. Jard et al., Mol. Pharmacol., 1986, 30, 171-177; Y. Arsenijevic et al., J. Endocrinol., 1994, 141, 383-391; J. Schwartz et al., Endocrinology, 1991, 129 (2), 1107-1109; Y. de Keyser et al., FEBS Letters, 1994, 356, 215-220), where they stimulate the release of adrenocorticotrophic hormone by AVP and potentiate the effects of CRF on the release of ACTH (G. E. Gdjjes et al., Nature, 1982, 299, 355). In the hypothalamus, the V1b receptors also induce a direct release of CRF (Neuroendocrinology, 1994, 60, 503-508) and are, in these various respects, implicated in stress situations.
These V1b receptors have been cloned in the rat, man and mouse (Y. de Keyser, FEBS Letters, 1994, 356, 215-220; T. Sugimoto et al., J. Biol. Chem., 1994, 269 (43), 27088-27092; M. Saito et al., Biochem. Biophys. Res. Commun., 1995, 212 (3), 751-757; S. J. Lolait et al., Neurobiology, 1996, 92, 6783-6787; M. A. Ventura et al., Journal of Molecular Endocrinology, 1999, 22, 251-260) and various studies (in situ hybridization, PCR (Polymerase Chain Reaction), and the like) reveal ubiquitous localization of these receptors in various central tissues (brain, hypothalamus and adenohypophysis, in particular) and peripheral tissues (kidney, pancreas, adrenal glands, heart, lungs, intestine, stomach, liver, mesentery, bladder, thymus, spleen, uterus, retina, thyroid, and the like) and in some tumors (hypophyseal or pulmonary tumors, and the like), suggesting a broad biological and/or pathological role of these receptors and potential involvement in various diseases.
By way of examples, in the rat, studies have shown that AVP, via the V1b receptors, regulates the endocrine pancreas, stimulating the secretion of insulin and of glucagon (B. Lee et al., Am. J. Physiol., 269 (Endocrinol. Metab. 32), E1095-E1100, 1995) or the production of catecholamines in the adrenal medulla, which is the site of a local synthesis of AVP (E. Grazzini et al., Endocrinology, 1996, 137 (a), 3906-3914). Thus, in the latter tissue, AVP, via these receptors, would have a crucial role in some types of adrenal pheochromocytomas which secrete AVP and which, for this reason, bring about a sustained production of catecholamines which are the cause of hypertension and which are resistant to angiotensin-II receptor antagonists and to converting enzyme inhibitors. The adrenal cortex is also rich in V1a receptors involved in the production of gluco- and mineralocorticoids (aldosterone and cortisol). Via these receptors, AVP (circulating or synthesized locally) can bring about production of aldosterone with an effectiveness comparable to that of angiotensin II (G. Guillon et al., Endocrinology, 1995, 136 (3), 1285-1295). Cortisol is a powerful regulator of the production of ACTH, the stress hormone.
The V1b receptors are also regarded as a label for ACTH-secreting tumors, which are some pituitary tumors and some bronchial (small cell lung cancers or SCLC), pancreatic, adrenal and thyroid carcinomas, resulting in some cases in Cushing's syndrome (J. Bertherat et al., Eur. J. Endocrinol., 1996, 135, 173; G. A. Wuinert et al., Lancet, 1990, 335, 991-994; G. Dickstein et al., J. Clin. Endocrinol. Metab., 1996, 81 (8), 2934-2941). The V1a receptors are, for their part, a more specific label for small cell lung cancers (SCLC) (P. J. Woll et al., Biochem. Biophys. Res. Commun., 1989, 164 (1), 66-73). Thus, the compounds according to the present invention are obvious diagnostic tools and offer a novel therapeutic approach in the proliferation and detection of these tumors, at an early stage too (radiolabeling; SPECT (Single Photon Emission Computed Tomography); PET Scan (Positron Emission Tomography Scan)).
The lavish presence of the messenger of the V1b receptors in the stomach and intestine suggests involvement of AVP via this receptor in the release of gastrointestinal hormones, such as cholecystokinin, gastrin or secretin (T. Sugimoto et al., Molecular cloning and functional expression of V1b receptor gene, in Neurohypophysis: Recent Progress of Vasopressin and Oxytocin Research; T. Saito, K. Kurokawa and S. Yoshida ed., Elvesier Science, 1995, 409-413).
1,3-Dihydro-2H-indol-2-one derivatives have been disclosed in some patent applications as ligands of the arginine-vasopressin and/or oxytocin receptors: mention may be made of Patent Applications WO 93/15051, EP 636 608, EP 636 609, WO 97/15556, WO 98/25901, WO 01/55130, WO 01/55134, WO 01/64668, WO 01/98295, WO 03/008407, WO 06/080574 and WO 08/025,735.
International application WO 95/18105 relates to compounds of formula:
in which in particular:                X represents SO2;        RI, RII, RIII, RIV, RV, RVI and q have different values.        
The compounds of formula (A) have an affinity for generally vasopressin and/or oxytocin receptors. In addition, this patent application does not describe any example in which RII is in the 6 position of the phenyl and represents a radical methoxy and RIV is always bonded in the 3 position of the indole-2-one ring via a nitrogen atom.
In particular, 3-[4-[[5,6-dichloro-3-(2-chlorophenyl)-2-oxo-3-[(2-(piperidin-4-yl)ethyl)amino]-2,3-dihydro-1H-indol-1-yl]sulfonyl]phenyl]-1,1-diethylurea (compound α) is described in Example 220 and 3-[4-[[5-chloro-3-(2-chlorophenyl)-6-methyl-2-oxo-3-[(2-(piperidin-4-yl)ethyl)amino]-2,3-dihydro-1H-indol-1-yl]sulfonyl]phenyl]-1,1-diethylurea (compound β) is described in Example 277 of WO 95/018 105.
Compound α exhibits a good affinity for human AVP V1a receptors but also for human AVP V2 receptors and oxytocin receptors; it is therefore not selective for human AVP V1a receptors and for human AVP V1b receptors.
Compound β exhibits a good affinity for human AVP V1a receptors but also for human AVP V2 receptors; it is therefore not selective for human AVP V1a receptors and for human AVP V1b receptors.